drivers/soc/actions/owl-sps-helper.c

   1 /*
   2  * Actions Semi Owl Smart Power System (SPS) shared helpers
   3  *
   4  * Copyright 2012 Actions Semi Inc.
   5  * Author: Actions Semi, Inc.
   6  *
   7  * Copyright (c) 2017 Andreas Färber
   8  *
   9  * This program is free software; you can redistribute  it and/or modify it
  10  * under  the terms of  the GNU General  Public License as published by the
  11  * Free Software Foundation;  either version 2 of the  License, or (at your
  12  * option) any later version.
  13  */
  14
  15 #include <linux/delay.h>
  16 #include <linux/io.h>
  17
  18 #define OWL_SPS_PG_CTL  0x0
  19
  20 int owl_sps_set_pg(void __iomem *base, u32 pwr_mask, u32 ack_mask, bool enable)
  21 {
  22         u32 val;
  23         bool ack;
  24         int timeout;
  25
  26         val = readl(base + OWL_SPS_PG_CTL);
  27         ack = val & ack_mask;
  28         if (ack == enable)
  29                 return 0;
  30
  31         if (enable)
  32                 val |= pwr_mask;
  33         else
  34                 val &= ~pwr_mask;
  35
  36         writel(val, base + OWL_SPS_PG_CTL);
  37
  38         for (timeout = 5000; timeout > 0; timeout -= 50) {
  39                 val = readl(base + OWL_SPS_PG_CTL);
  40                 if ((val & ack_mask) == (enable ? ack_mask : 0))
  41                         break;
  42                 udelay(50);
  43         }
  44         if (timeout <= 0)
  45                 return -ETIMEDOUT;
  46
  47         udelay(10);
  48
  49         return 0;
  50 }
  51 EXPORT_SYMBOL_GPL(owl_sps_set_pg);